TY - JOUR T1 - Dimethyl fumarate decreases neurofilament light chain in CSF and blood of treatment naïve relapsing MS patients JF - Journal of Neurology, Neurosurgery & Psychiatry JO - J Neurol Neurosurg Psychiatry SP - 1324 LP - 1330 DO - 10.1136/jnnp-2019-321321 VL - 90 IS - 12 AU - Tobias Sejbaek AU - Helle Hvilsted Nielsen AU - Natasha Penner AU - Tatiana Plavina AU - Jason P Mendoza AU - Nellie Anne Martin AU - Maria Louise Elkjaer AU - Mads Henrik Ravnborg AU - Zsolt Illes Y1 - 2019/12/01 UR - http://jnnp.bmj.com/content/90/12/1324.abstract N2 - Objectives In a prospective phase IV trial of the first-line oral treatment dimethyl fumarate (DMF), we examined dynamics of neurofilament light (NFL) chain in serum, plasma and cerebrospinal fluid (CSF) samples collected over 12 months from relapsing-remitting multiple sclerosis (RRMS) patients. NFL changes were related to disease activity.Methods We examined NFL levels by single-molecule array in 88 CSF, 348 plasma and 131 sera from treatment-naïve RRMS patients (n=52), healthy controls (n=23) and a placebo group matched by age, sex and NFL (n=52). Plasma/sera were collected at baseline, and 1, 3, 6 and 12 months after DMF. CSF samples were collected at baseline and 12 months after DMF.Results NFL concentration in CSF, plasma and serum correlated highly (p<0.0001 for all), but plasma levels were only 76.9% of paired serum concentration. After 12 months of DMF treatment, NFL concentration decreased by 73%, 69% and 55% in the CSF, serum and plasma (p<0.0001, respectively). Significant reduction in blood was observed after 6 and 12 months treatment compared with baseline (p<0.01 and p<0.0001, respectively) and to placebo (p<0.0001). Patients with NFL above the 807.5 pg/mL cut-off in CSF had 5.0-times relative risk of disease activity (p<0.001).Conclusions This study provides Class II evidence that first-line DMF reduces NFL in both blood and CSF after 6 months and normalises CSF levels in 73% of patients. High NFL concentration in CSF after a year reflected disease activity. NFL levels were higher in serum than in plasma, which should be considered when NFL is used as a biomarker. ER -